<template>
    <div>
        <router-link tag="div" to="/" class="header-abs" v-show="showAbs">
            <div class="iconfont header-abs-back">&#xe624;</div>
        </router-link>
        <div class="header-fixed" v-show="!showAbs" :style="opacityStyle" >
            <router-link to="/">
                <div class="iconfont header-fixed-back">&#xe624;</div>
            </router-link>
            景点详情
        </div>
    </div>
</template>

<script>
export default {
    name: 'DetailHeader',
    data () {
        return {
            showAbs: true,
            opacityStyle: {
                opacity: 0
            }
        }
    },
    methods: {
        handleScroll () {
            const top = document.documentElement.scrollTop
            if (top > 60) {
                let opacity = top / 140
                opacity = opacity > 1 ? 1 : opacity
                this.opacityStyle = {
                    opacity
                }
                this.showAbs = false
            } else {
                this.showAbs = true
            }
        }
    },
    activated () {
        window.addEventListener('scroll', this.handleScroll)
    },
    deactivated () {
        window.removeEventListener('scroll', this.handleScroll)
    }
}
</script>

<style lang="scss" scoped>
    @import '../../../assets/styles/varibles.scss';
    .header-abs {
        position: absolute;
        left: .2rem;
        top: .2rem;
        width: .8rem;
        height: .8rem;
        line-height: .8rem;
        border-radius: .4rem;
        text-align: center;
        background: rgba(0, 0, 0, .8);

        .header-abs-back {
            color: #fff;
            font-size: .4rem;
        }
    }

    .header-fixed {
        z-index: 2;
        position: fixed;
        top: 0;
        left: 0;
        right: 0;
        height: $headerHeight;
        line-height: $headerHeight;
        text-align: center;
        color: #fff;
        background:  $bgColor;
        font-size: .32rem;

        .header-fixed-back {
            position: absolute;
            top: 0;
            left: 0;
            width: .64rem;
            text-align: center;
            font-size: .4rem;
            color: #fff;
        }
    }
</style>

